I'm having problems with 1/2" x 15mm lockshield/manual radiator valves that I've bought from one of the major suppliers who mainly sells goods originating from China or India. Apart from the first lot which came in individual bags labelled as 1/22 X 15 but contained 1/2" X 10 they've sent 3 replacement sets of valves all of which were incredibly stiff and which my local plumber said that they were unusable.
The seller claims that their Quality Assurance people have checked them and said that they are OK.
I've knocked up a lash-up rig to test the torque required to move the valve which was 2.3 Newton metres from the closed position or 1.4 at mid range. I understand that British Standard 2767:1991 "Specification for manually operated copper alloy valves for radiators" gives figures for the torsion range but at £134 I'm reluctant to buy a copy just to prove a point. If anyone has a copy I'd be very grateful if they could let me have that information.
The seller does not claim that their valves meet the BS but, if as I suspect, the measured torque wildly exceeds the BS then I may be able get them to supply properly working valves.
The seller claims that their Quality Assurance people have checked them and said that they are OK.
I've knocked up a lash-up rig to test the torque required to move the valve which was 2.3 Newton metres from the closed position or 1.4 at mid range. I understand that British Standard 2767:1991 "Specification for manually operated copper alloy valves for radiators" gives figures for the torsion range but at £134 I'm reluctant to buy a copy just to prove a point. If anyone has a copy I'd be very grateful if they could let me have that information.
The seller does not claim that their valves meet the BS but, if as I suspect, the measured torque wildly exceeds the BS then I may be able get them to supply properly working valves.
